The second half of the twentieth century has witnessed several waves of democratization in Europe, the Americas, and in other regions of the world, such as South East Asia. Although for the most part these democratic regimes are no longer haunted by the prospect of a return to authoritarianism, severe economic and social problems have posed serious challenges, creating a situation where change is often achieved through alternating periods of consolidation and crisis. Drawing on a systematic, empirical analysis of four key Southern European countries, Portugal, Spain, Greece, and Italy, Morlino identifies several key aspects of democratic consolidation: consensus and legitimation, party system and party organization, and the ways in which organized and non-organized interests are related to parties and the institutions of state. The resulting models of consolidation are analysed and the mechanisms and patterns of their unfolding crises identified, taking care to disentangle the pragmatic reactions against the regime, often related to corruption, from more ideological ones grounded in differences in values. Finally, the author addresses the question of the 'quality' of democracy, examining how this is related to the outcome of processes of consolidation and crisis. This insightful study offers the first extensive, comparative analysis of consolidation and crisis in these countries, and features a wealth of up-to-date information on party organizations, interest associations, the media, and public opinion. Although clearly focusing on Southern Europe, the author's findings are extremely relevant for understanding the politics of several other regions, including Eastern Europe, Latin America, and South East Asia.